Railroad track rails are subject to wear by the passage of trains over the rails. In particular, depressions in the upper surface of a rail may develop such that the railhead presents a modulating, corrugated surface. Moreover, the rail may develop burrs or otherwise lose its symmetrical profile. Maintenance of smooth running surfaces on railroad track rails is important for reasons of safety, riding comfort, protection of the track, track bed and rolling stock, noise suppression, and reduced maintenance of the track and track bed.
Grinding machines have been developed for maintaining railroad track rails in smooth, properly shaped condition. Such grinding machines generally comprise a plurality of rotatable grinding modules carried by a locomotive or the like in close proximity to the railhead surfaces of the track rail. The grinding modules include rotatable, abrasive grinding stones that can be lowered into a position flush with the rail surface to grind and restore the rail surface to a smooth, desired profile.
The operation of grinding railroad track rails with abrasive stones necessarily produces sparks, metal tailings, and grinding stone residue. The sparks present a fire hazard as well as a safety hazard to personnel involved in the grinding operation. Often, the mere threat of a fire hazard in extremely dry areas may require the cessation of grinding activities, prolonging the time to accomplish necessary track maintenance and increasing maintenance costs.
A number of designs have been proposed to contain, suppress or evacuate the sparks, residue, and dust that are the byproducts of railroad rail grinding. Grinding machines have been fitted with metal flaps on the field sides of the machines in proximity to the grinding stones. Such flaps are effective in containing some of the byproducts by presenting a physical barrier. U.S. Pat. No. 4,583,327 to Jaeggi discloses a rail grinding machine wherein the grinding stones are surrounded by shrouds. A source of negative pressure is connected to the shrouds to pull dust and sparks away from the grinding area. European Patent Publication No. 0 070 359/B1 assigned to Speno International S.A. discloses a grinding machine wherein a steam mist is directed by nozzles toward the vicinity of the grinding area. U.S. patent application Ser. No. 464,127 assigned to the assignee of the present application, discloses a grinding machine wherein water is sprayed by specially designed and positioned nozzles in the vicinity of the grinding area.
The generation of dust from the rail grinding process has recently come under the scrutiny of several governmental agencies concerned with maintaining air quality standards. The governmental interest in maintaining air quality, together with the continuing hazard of fire associated with rail grinding, has caused the rail grinding industry to redouble its efforts to find effective methods and devices for controlling the byproducts of the rail grinding process.